Age- and Time-Related Changes in Serum Ferritin in Danish Men: A Population-Based Longitudinal Study of 1,199 Men Over a 10-Year Period: Influence of Nutritional Factors

Abstract

Background: A balanced body iron status is essential for good health. This longitudinal panel study assessed iron status in Danish men over a 10-year-period.

Methods: The study was part of the WHO DAN-MONICA health survey in Copenhagen 1982–1994, comprising 1,199 healthy men in age groups of 30, 40, 50, and 60 years, being invited for examination three times: at inclusion and 5 and 10 years later. Blood samples were analyzed for hemoglobin and serum ferritin as surrogates for iron status.

Results: Serum ferritin levels became stable between 35 and 40 years of age. In all age groups (except in 60-year-old men), ferritin levels increased significantly from baseline to the end of the study. Concurrently, the frequency of high ferritin values > 300 µg/L increased significantly and the frequencies of low ferritin values < 30 µg/L decreased. There was an overall increase in ferritin levels in 40-, 50-, and 60-year-old men in MONICA 10 compared to men of similar age in MONICA 1. Blood donors had significantly lower ferritin levels than non-donors in all age groups, but few had iron deficiency anemia.

Conclusions: There were no indications that the rise in ferritin during the 10-year period was caused by a higher frequency of inflammatory conditions. The increase was most likely due to changes in lifestyle factors, especially nutritional factors, considering that dietary iron intake in men is markedly higher than the recommended daily intake and due to an increase in the consumption of meat and alcohol in the observation period. This study suggests that in a population, ferritin should be monitored with appropriate intervals in order to evaluate changes in iron status.